Sputtering Yields at Very Low Bombarding Ion Energies

The spectroscopic method has been used to study sputtering yields under normally incident ion bombardment at very low ion energies. Data have been extrapolated to determine threshold energies for sputtering under normal incidence. These estimated thresholds are approximately the same energy (roughly four times the heat of sublimation) as the displacement thresholds for radiation damage. The mass ratio between ion and target atoms plays hardly any role in the thresholds.